title: Regional hepatic regeneration after liver resection correlates well with preceding changes in the regional portal circulation in humans.
abstract: OBJECTIVE
  While portal hemodynamics largely affects the liver regeneration after partial hepatectomy, whether the remnant liver homogeneously regenerates is unclear, especially in humans. We hypothesized that change in flow distribution varies in each remnant portal branch after liver resection in humans and the liver consequently regenerates heterogeneously.
  
  
  METHODS
  Twenty-two patients who underwent anatomical hepatic resection preserving intact drainage veins were analyzed. Based on perioperative contrast-enhanced computed tomography, the regional hepatic regeneration in each segment was analyzed using a region growing software. The perioperative change in the distribution of blood flow in each portal branch was assessed using the computational flow dynamics technique. The correlation between the change in the portal flow distribution and the later regional hepatic regeneration was investigated.
  
  
  RESULTS
  The distribution of portal blood flow in each remnant branch largely changed at 2 weeks (71-389 %). Each remnant segment also heterogeneously regenerated at 3 months (85-204 %). Meanwhile, a good correlation between the regional regeneration rate at 3 months and the relative change in the flow distribution in each circulating portal branch at 2 weeks was detected in each patient (r = 0.74-0.99).
  
  
  CONCLUSIONS
  After partial hepatectomy, the change in blood flow varies in each remnant portal branch and the liver heterogeneously regenerates in humans. The good correlation between the earlier change in the portal flow distribution and the later regional hepatic regeneration strongly suggests that the portal venous flow most likely regulates the non-uniform liver regeneration after hepatic resection in humans.
authors.affiliation: Department of Surgery, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo, 663-8501, Japan, siimuro@hyo-med.ac.jp.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Iimuro
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kondo
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Suzumura
authors.forename: Naoki
authors.initials: N
authors.lastname: Uyama
authors.forename: Yasukane
authors.initials: Y
authors.lastname: Asano
authors.forename: Tadamichi
authors.initials: T
authors.lastname: Hirano
authors.forename: Junichi
authors.initials: J
authors.lastname: Yamanaka
authors.forename: Hiroko
authors.initials: H
authors.lastname: Iijima
authors.forename: Shuhei
authors.initials: S
authors.lastname: Nishiguchi
authors.forename: Jiro
authors.initials: J
authors.lastname: Fujimoto
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000601:surgery; D001653:Bile Ducts, Intrahepatic; D006528:Carcinoma, Hepatocellular / Q000601:surgery; D018281:Cholangiocarcinoma / Q000601:surgery; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006498:Hepatectomy; D006801:Humans; D008099:Liver / Q000098:blood supply* / Q000601:surgery*; D008113:Liver Neoplasms / Q000601:surgery; D008115:Liver Regeneration / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011169:Portal Vein / Q000000981:diagnostic imaging / Q000502:physiology*; D012039:Regional Blood Flow / Q000502:physiology*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography